Why did AOS only build my Home page?

That's on purpose: AOS builds Home first, then you direct the other pages, so your site says what you want instead of what a template guesses.

When Home is done, the build screen says Home is done. You direct the rest. Each suggested page (usually Services, About and Contact) needs one line from you about what it should say. You can rename a page, cut one or add your own, up to 4 pages including Home. Once every page has its line, tap Build my pages and AOS builds them in Home's design.

After you go live you can add more pages from the editor, up to your plan's limit.